The present disclosure relates to a method for stabilizing a cavity in a well.
Stabilizing open annuli in production and injection wells helps avoid sand production. Today, this is usually done by gravel packing Gravel and/or sand is packed around a sand screen or a perforated casing to function as a sieve by preventing finer sand from the formation from being carried in the petroleum into the well. Another alternative has been to stabilize formation sand by supplying resinous materials to “glue” the formation together.
During gravel packing, there is a substantial risk of failure when placing the sand/gravel pack, especially in long horizontal wells. It may be challenging to place sand and gravel packs in production and injection wells in which packers divide the annulus along the well path into several production or injection intervals. In addition, stabilizing the annulus for several production or injection intervals can be difficult when there are inflow or outflow valves along the well path, and different pressure conditions in the different formations that divide the well into several zones. Today, casing is cemented and perforated and cannot be completed with sand screens in the entire production or injection interval. Further, it is only the lowermost part of the well that is gravel packed. There is also a substantial risk of erosion on pipes and equipment in the well if the sand/gravel pack leaks through the sand screen or a perforated casing. If the annulus is closed naturally by the formation sand in one or more places along the well path, the entire well length cannot be sand/gravel packed in a satisfactory manner, and the gravel packing will be incomplete. When the formation sand is glued, it is then fractured to enable production. This method is time-consuming and the directions of the fracture systems are not predictable. Thus, a risk arises that the well does not produce/inject in the right formation intervals. In sum, the known methods are generally expensive, complicated and not very flexible.